Impact of past and future climate change on crop yield, nitrate leaching and nitrous oxide emissions associated with potato rotation in temperate climate

The demand for production of potato is expected to continue to increase in the future; however climate change can impact both its growth and its environmental footprint, and thus its sustainability. In this study, we analyzed the dynamics of crop yield, nitrate (NO3) leaching and nitrous oxide (N2O) emissions associated with potatobarley-red clover rotation in a temperate humid climate in Price Edward Island, Canada between 1950 and 2100. We employed the Root Zone Water Quality Model (RZWQM) in conjunction with meteorological forcing data from regional climate model simulations associated with five Global Warming Levels (i.e.; GWL; past climate: 0.2 and 0.4 degrees C; reference period: 0.85 degrees C [1995-2014]; future climate: 2.0, 3.0 and 4.0 degrees C increase in temperature relative to preindustrial conditions). Past climate change had muted impacts, while future change had mixed impacts. Thus, potato tuber yield is projected to be minimally impacted by future climate change (i.e.; -1.72 to 5.03 % change compared to the reference period), barley yield will be negatively (i.e.; -1.91 to -23.9 %) and red clover biomass will be positively (i.e.; 6.26-10.0 %) impacted. NO3 leaching is projected to increase by 23.5 % and N2O emissions by 32.9 % at the rotation level for the same period. Additionally, significant seasonal changes in the dynamics and magnitude of these processes were observed. The potential impacts identified suggest that substantial efforts should be undertaken for developing adaptation strategies for maintaining agricultural production and minimizing environmental losses associated with this rotation, and with potato cropping systems in general.